Hydraulically actuated bucket closing means



HYDRAULIOALLY AGTUATED BUCKET cnosme mums Filed Sept. 24. 1968 Nov. l 8,' 1969 R. w. MARTIN ETAL 6 Sheets-Sheet 1 N 18 9 R. w. MARHN Em 3,479,011

HYDRAULICALLY ACTUATED BUCKET CLOSING MEANS Filed Sept. 24,- 1968 6 Sheets-Sheet 2 m mm m mm... 1 .P Q N vm u mm EN BH 0O R v 1969 R, w. MARTIN ETAL 3,479,077

HYDRAULICALLY ACTUATED BUCKET CLOSING MEANS Filed Sept. 24, 1968 6 Sheets-Sheet 3 INVENTORS ROBERT W. MARTIN BY JOHN; SPEARS m ,M I 9 AGENT HYDRAULIGALLY ACTUATED BUCKET CLOSING MEANS Filed Sept. 24. 1968 Nov. 18, 1969 R. w. MARTIN ETAL 6 Sheets-Sheet 4 ROBERT! MARTIN JOHN R. SPEARS HYDRAULICALLY ACTUATED BUCKET CLOSING MEANS R. W- MARTIN ETAL Nov. 18, 1969 6 Sheets-Sheet 5 Filed Sept.

lNvENTORs ROBERT W. MARTIN JOHN R SPEARS AGENT HYDRAULICALLY ACTUATED BUCKET CLOSING MEANS Filed Sept. 24. 1968 R. W- MARTIN ETAL Nov. 1 8, 1969 6 Sheets-Sheet 6 ROBERT W. MARTIN JOHN R SPEARS United States Patent O 3,479,077 HYDRAULICALLY ACTUATED BUCKET CLOSING MEANS Robert W. Martin, 7102 NE. 63rd Ave., Vancouver,

Wash. 98661, and John R. Spears, 9 McCain St., Astoria, Oreg. 97103 Continuation-impart of application Ser. No. 653,460, July 14, 1967. This application Sept. 24, 1968, Ser. No. 767,913

Int. Cl. B66c 3/16 US. Cl. 294-70 16 Claims ABSTRACT OF THE DISCLOSURE A hydraulically actuated cylinder adapted for suspension from the hoisting line of a crane and having its piston rod attached to a closing pennant of a clam shell bucket, to permit closing force to be exerted on the clam shell bucket in place of the usual drum powered closing line which conventionally is reeved through a block and tackle closing arrangement. The cranes closing line instead actuates a second hydraulic cylinder to cause pressurized fluid to be directed to the first mentioned hydraulic closing cylinder. The closing cylinder is supported within a housing carried by the cranes hoisting line, the housing being hingedly connected to the bucket to permit proper bucket positioning relative to the dredged material and regardless of obstructions or incline of the dredging area. The invention may alternately 'be used for precise hoisting or discharging of other heavy loads through remote control of the closing cylinder. An engine driven source of hydraulic pressure may be put in circuit with the closing cylinder to permit dispensing with the normal closing line of the crane and wherein closing of the clam shell bucket will be through a valve control.

BACKGROUND OF THE INVENTION This is a continuation-in-part of our joint application Ser. No. 653,460 filed July 14, 1967, now abandoned.

The present invention relates to an attachment for cranes normally having a hoist line and a closing line wherein said closing line may be rigged to engage a source of hydraulic pressure to permit pressurization of another hydraulic cylinder disposed adjacent to the clam shell bucket for closing same.

In existing clam shell bucket arrangements the crane is rigged with a line known as a hoist line terminating at its end in attachment with the stationary part or head of a bucket. A second line known as a closing line is normally reeved through a series of sheaves constituting a block and tackle carried by the bucket for multiplying the closing force necessary to close a loaded bucket. In the operation of a conventional clam shell bucket the hoisting line and closing line must be retrieved at the same speed to retain the clam shells in a closed position while lifting and swinging the same to a discharge site. A considerable degree of crane operator skill is necessary to properly retrieve both the lifting and closing lines to prevent inadvert separation of the clam shells and loss of the load. In the present invention the two operations, that is the hoisting of the bucket assembly and closing operation, are completely separate and do not require any particular high degree of operator skill for satisfactory operation.

A further disadvantage of the conventional hoisting rigging for clam shell buckets resides in the fact that such buckets are necessarily suspended by a single run of the hoist line thus limiting the bucket size to the single line pull capacity of the hoisting cable. The present invention permits disconnecting of the closing line from the bucket and thereby allows the remaining hoisting line to be doubled back and dead ended adjacent the booms outer end or, to further increase the load capability, reeved in a block and tackle manner. The doubling back or utilizing a block and tackle arrangement obviously increases the load capabality in multiples of the single line pull capacity up to the cranes limitation. Heretofore in view of the closing line such has not been possible.

A further and very significant advantage of the present hydraulic closing means is the novel utilization of the reaction force of the hydraulic closing cylinder to assure efiicient penetration of the clam shell members during closing into the material being loaded. In the loading of hard'packed material the buckets weight alone in conventional arrangements is ordinarily insufficient to secure a full bite or load. The present arrangement prevents undesirable upward movement of the pairs of bucket arms to assure full penetration and loading of the bucket.

A further object resides in a novel housing for the hydraulic cylinder which is hingedly attached to the hoist line and oppositely to the bucket at its lower end. The hinged means provided allows the bucket to assume a most efiicient pre-closing position in relation to the material being moved regardless of underwater obstructions or inclined surfaces being dealt with, such causing conventional buckets to assume an other than perpendicular relationship to the ground and hence an ineflicient closing action. Also, the closing cylinder and its piston rod are protected from contact with the material being loaded.

An additional object is achieved by providing remote control means at the loading site to permit a workman at the site to precisely adjust the height of the loading attachment to the material to be lifted. A still further object resides in the quick changeover feature wherein the crane may be readily converted from a clam shell dredging op- H eration to a hoisting operation wherein the usual timeconsuming and hence costly rigging changes are avoided.

Further important features of the present invention reside in the provision of a bucket particularly eflicient in the digging or dredging of inclined ground surfaces. The hinged movement of the bucket about the axis of attachment to its closing means permits the bucket to be dropped into perpendicular relationship with an inclined surface being dealt with and upon initiating of bucket closing the two clam shells are equally driven into biting engagement with the sloped material. The downward reaction of the slave cylinder incident to closing of the bucket is utilized to facilitate full penetration of the clam shells into crusty or hard surfaces.

The hydraulic closing means provided further may be related to the bucket in a manner providing for a desirable low center of gravity to insure bucket stability on uneven ground.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side elevational view of the present invention operably disposed in association with the boom and hoisting line of a crane,

FIGURE 1A is a side elevational view of the upper portion of the crane boom and shown supporting the present invention by means of a hoisting line reeved into block and tackle arrangement,

FIGURE 2 is an enlarged detail view of a clam shell bucket with the novel closing means of the present invention applied thereto,

FIGURE 3 is a sectional view taken approximately along line 3-3 of FIGURE 2 showing the roller guides for the closing pennant cable,

FIGURE 4 is a fragmentary view of the boom equipped with a hydraulic cylinder rigged for actuation by the closfora hoisting operation with control means provided for operation .by anindividual at the loading site,

FIGURE 6 is a sectional view of the upper end of the hydraulic cylinder within its housing and further showing internal construction of the piston therein,

FIGURE 7 is a schematic view of a modified form of the invention wherein a pump is utilized as a source of hydraulic pressure for the remotely located hydraulic closing cylinder,

FIGURE 8 is a view similar to FIGURE 1 showing a modified form of the invention,

FIGURE 9 is a fragmentary, side elevational view of the bucket assembly and the closing means of FIGURE 8 shown digging material from a sloping surface,

FIGURE 10 is a side elevational view of the modified bucket closing means of FIGURE 8,

FIGURE 11 is an elevation of FIGURE 10 rotated through 90 degrees,

FIGURE 12 is a horizontal sectional view taken along line 12-12 of FIGURE 11 showing the cable lift trolley 'and angle iron guides therefor,

7 FIGURE 13 is a horizontal sectional view taken along line 13-13 of FIGURE 11 showing the slave hydraulic closing cylinder within its housing,

FIGURE 14 is a lower perspective view of the bucket head adapter with sheaves removed,

FIGURE 15 is a plan view of the bucket head adapter,

FIGURE 16 is a side elevational View of the bucket head adapter with fragments broken away to show the attachment of a conventional bucket head to the present invention,

FIGURE 17 is a side elevational view of a modified gimbal mounting of the bucket assembly to the closing means at a point upwardly spaced from the lower end of said closing means,

FIGURE 18 is a front elevational view of FIGURE 17 taken along line 18-18, and

FIGURE 19 is a hydraulic schematic of the invention of FIGURES 1 and 8.

DESCRIPTION OF THE PREFERED EMBODIMENTS With continuing reference to the drawings and particularly FIGUES 1 and 1A thereof, the reference numeral 1 indicates generally a crane which includes a boom member 2 hingedly mounted within the cab of the crane and provided with sheaves 3 at the booms outer end. In continuing similarity to conventional crane construction a boom line is indicated at 4. The cab of the crane is mounted on a turntable which in turn may be supported by a floating platform such as a barge. The cab of the crane conventionally houses a pair of powered drums independently operable for the hoisting and the closing of a clam shell bucket. The hoisting line or cable carried by one of the drums is indicated at 5 and extends past one of the sheaves 3 at the outer end of the boom and downwardly through a pulley block 6 and thence upwardly into dead-ended attachment at 7 adjacent the outer end of the boom. A closing line 8 is carried by the other drum within the cranes cab and is also reeved through one of the sheaves indicated at 3 and thence downwardly along the underside of the boom 2 preferably to a block associated in a block and tackle arrangement indicated generally at 9. It will be readily understood that the reeving of the hoisting and closing lines above described is different from the usual clam shell arrangement wherein a hoisting line terminates in supporting attachment to the clam shell bucket while the closing line is usually connected with a block and tackle arrangement within a cleam shell bucket.

In a typical clam shell dredging operation, ideally, an equal upward force is exerted on the clam shell bucket by both the hoisting line and the closing line and, accordingly, each line must be a single line for purposes of equal retrieval speed. In the present invention the hoisting line may be, as shown in FIGURE 1, doubled or in FIGURE 1A may be made part of a block and tackle to increase the bucket lifting capacity in multiples of the single line pull limitation of the cable.

Bucket closing means is indicated generally at 10 and is in universal suspended attachment as at 11 by the pulley block 6. The bucket closing means 10 further comprises an elongated tubular housing 12 open at its bottom end and housing a hydraulic closing or slave cylinder 13 having a piston rod 13A. The hydraulic closing cylinder 13 is of single acting type wherein a source of fluid pressure is in communication with the lower end of the cylinder for powering the piston rod 13A in an upward direction. Tubular housing 12 carries a bar 14 welded thereto and extending lengthwise and beyond the housing ends terminating in universal components at 15 similar to those at 11 above said housing. The bar is concave along one of its sides for nested securement along the housing wall. The clam shell bucket is indicated generally at 16 in universal suspended attachment at 15 and including conventionally formed clam shells scoop members 17 swingably supported in the usual manner by pairs of arms 18 hingedly carried by a head plate 21. It will be noted, however, with regard to FIGURE 2 that the block and tackle closing arrangement has been removed from the bucket and a single run of cable constituting a flexible closing pennant 19 substituted therefor. The pennant extends upwardly from the hinged center section 17A of the bucket through roller means 20 in the head plate 21 and into the lower end of the tubular housing 12. The pennant terminates in an attachment fitting secured to the outer end of the piston rod 13A by means of a clevis plate 22. Roller means 23 are additionally provided in the lower end of the housing 12 to prevent the pennant from coming into contact with the housing during dredging operations when the latter is tilted from the vertical. The rollers 23 are journalled within reinforced portions of the housing 12A and are positioned below the lowest extent of travel of the piston rod 13A.

With continued attention to FIGURE 2 and additionally FIGURE 6, it will be seen that the upper end of the closing cylinder 13 is retained within the housing by a friction tight pin 24 which extends horizontally through a solid cap 25 of the housing and through an aperture in a mounting plate 13B of the cylinder. The mounting plate 13B additionally defines an aperture at its exposed end for purposes later elaborated upon. A fluid supply conduit at 26 is in communication by means of a fitting 27 with the lower end of cylinder 13 to admit fluid below the underside of the cylinders piston 28 (FIG. 6). From the foregoing it will be seen that hydraulic fluid under pressure admitted to the lower end of the cylinder 13 will cause upward movement of both the piston rod 13A and closing pennant 19, resulting in closing of the clam shell members 17.

As seen in broken lines in FIGURE 2, closing of the bucket may be accomplished by reason of the flexible pennant 19 and universal attachment with the housing 12 in an inclined position relative to bucket 16 as could occur in a dredging operation as a result from encountering an under water obstacle or in dredging the bottom of a body of water having a steeply sloping surface.

Simultaneously with the raising of pennant 19 to close the bucket, a downward force is exerted upon the clam shell members through the universal attachment point 15, head plate 21 and arms 18. This downward force is applied concurrently with, but opposite to, the lifting force exerted by pennant 19 on the buckets center section 17A" by means of the opposite reaction of the cylinder 13 upon being pressurized. The arms 18 of the bucket are accordingly biased downwardly during closing of the clam shell members 17 to accomplish efficient penetration of said members even in instances where the dredged material is of a cementitious or crusty nature wherein the weight of the bucket itself is lnsufficient for adequate penetration.

The structure above described provides hydraulic bucket closing means wherein the hydraulic cylinder 13 and its rod 13A are advantageously removed from the clam shell bucket members and thereby protected from coming into forceful and damaging contact with the material being dredged. The pennant 19 being of flexible cable permits imparting closing action to the bucket along plural vectors such as is the case when the bucket and closing means are disposed in the broken line relationship of FIGURE 2. Further the closing cylinder 13 and its piston rod are concealed at all times within the protective tubular housing 12.

The preferred form of pressure generating means for pressurizing the single acting closing cylinder 13 above described includes a control or master cylinder 30 in circuit with cylinder 13 and carried by boom 2 on the underside thereof and having a piston rod 31 carrying a pulley block 32 of the previously mentioned block and tackle arangement 9. Cylinder 30 is rigidly attached by bracket means as at 33 and is vented to the atmosphere through an orifice 34 located at its lower end. In the present circuit the piston rod 31 is extended by means of the cranes closing line 8 which is entrained through pulley block 32 carried by the piston rod and terminates in attachment with an upper block 35 to constitute the block and tackle arrangement 9. The last mentioned block is secured by a gusset plate 36 to the underside of the boom.

The piston rod end of master cylinder 30 is in communication through a pressure relief valve 38 with a fluid conduit including a supply line 39, the latter in turn connected to the flexible hose or conduit 26 through a hose reel 41 rotatably mounted on boom 2. Pressure relief valve 38 is also connected by a line 42 with a fluid reservoir 43. A quantity of hydraulic fluid occupies, as aforesaid, the lower or rod side of the first described closing or slave cylinder 13, flexible hose 26, supply line 39 and the rod or upper end of master cylinder 30. Accordingly, upon retrieval of the cranes closing lines in the conventional manner by the powered drum within the cab the block 32 will be moved upwardly from its position shown in FIGURES 1 and 4, thereby pressurizing the hydraulic fluid within the immediately above-described circuit. Pressure accordingly is transmitted to the rod side of cylinder 13 to move piston 28 upwardly causing like movement of piston rod 13A and the closing pennant 19 ultimately causing the clam shell members 17 connected thereto to close together against the resistance of the material being dredged. The pressure relief valve 38 associated with the cylinder 30 is pre-set to divert hydraulic fluid into the reservoir 43 for relieving the system at a predetermined pressure. Should an underwater obstruction be encountered by the clam shells, preventing their closing, continued upward movement of block 32 by the closing line will result in the hydraulic fluid being diverted into the reservoir to safeguard the circuit from excessive pressure.

It will be noted that the piston stroke of cylinder 30 is suflicient to fully actuate the closing cylinder to close the clam shell members as above described with any excess hydraulic fluid being diverted into the reservoir 43. The additional area in the cylinder 30 also insures adequate fluid volume to compensate for any gradual fluid lost in the cylinders.

In the bucket closing operation above described, a head of compressed air will be formed ahead or above the piston 28 of closing cylinder 13 when the piston is at its upper limit of travel, as shown in FIGURE 6, to form a chamber 45. In a typical dredging operation subsequent to closing of the clam shell members, the bucket is raised clear of the water and swung to a discharge site, this being accomplished solely by retrieval of the hoist line which may or may not be reeved through a block and tackle arrangement as earlier noted. Upon sulting decrease in pressure within cylinder 30 the internal reaching the dumping or discharge site, the crane operator will release the brake means associated with the powered closing drum to permit piston rod 31 and the lower block 32 attached thereto to be retracted by reason of the hydraulic pressure within the circuit. With the repressure within closing cylinder 13 is reduced to a point where the several thousand pound bucket load in combination with the air pressure in chamber 45 will act to extend piston rod 13A permitting the closing pennant to move downwardly through the bucket head plate 21 to rapidly release the clam shell members. The stroke of piston rod 13A is such that complete opening of the clam shell members 17 will occur before the piston 28 reaches its downward limit of travel. After discharge of the material the clam shells will remain in their open loadreceiving position by gravity until initiation of the second loading operation.

With particular reference to FIGURE 6, provision has been made for returning any hydraulic fluid which may have collected through internal leakage upwardly past the piston 28. To accomplish this a ball check valve 50 is unseated to permit hydraulic fluid to be returned to the underside of the piston 28 upon the latter coming into engagement with a centrally disposed projection 51 mounted within the upper end of cylinder 13. The upper side of piston 28 is cupped as at 52 and centrally relieved at 53 to receive the projection 51. Accordingly, fluid that has accumulated in relieved area 53 will be returned to the underside of piston 28 upon a reduction of the hydraulic pressure incident to the discharge operation with the pressurized trapped fluid unseating the check valve 50 to return any hydraulic fluid.

A modified hydraulic circuit is shown in schematic form in FIGURE 7 wherein a pump 55 is mounted within the cab of the crane to pressurize the closing cylinder 13 thus permitting dispensing with a closing line in its entirety. The modified hydraulic closing circuit includes the pump 55 in circuit with an accumulator 56, served by a conduit 57. The constant pressure from the accumulator is delivered to an operator-controlled, two-way valve 59. A pressure supply line 58 terminates in the hose drum 41 previously described, which carries the flexible hose 26. The valve means 59 is of the two-position type to permit relieving of fluid pressure in the conduit means to the reservoir R by conduit 61.

With reference to FIGURE 5, the bucket 16 may be detached from the bucket closing means 10 at the lower universal attachment 15 and thereby capable of serving as a hoist component. The block 6 in this modified form is removed from its universal attachment at 11 with bar 14 and attached to the exposed aperture in mounting plate 13B of the closing cylinder 13. Accordingly, the crafie may be readily converted from a dredging operation to a hoisting operation using either of the previously described hydraulic circuits without the time-consuming re-reeving of the hoist and closing lines as required with conventional cranes. In this modified form of the invention the hydraulic pressure is transmitted to the lower side of cylinder 12 through the flexible conduit indicated at 26 and in addition thereto through a secondary circuit providing remote control means for cylinder 13 at the loading site. Said secondary circuit comprises a manually operated flow control valve 62 served by conduits 26A and 26B with the latter terminating in communication with fitting 27. A ported block 63 is combined with the fitting 27 for directing fluid flow through the conduits 26A-26B with the flow being regulated by manipulation of valve 62 for precise positioning of a load carrying hook 65 in a loading or unloading operation. This conduit 26 may include control means 62 for remote control of the cylinder 13 by a workman at the loading site. Precise vertical positioning of a loading hook at 65 is thereby afforded.

With regard to the modified form of the invention in FIGURES 8 through 18 the hydraulic closing means therein generally at 70 is shown suspended from a hoist line 71 of a crane similar to that shown and described in regard to the first form of the invention. The crane in FIGURE 8 in continuing similarity includes a closing line 72 which along with hoisting line 71 is entrained respectively through plural sheaves 73 at the tip of the boom 74. A boom line is indicated at 75.

The closing means 70, with additional attention being directed to FIGURES and 11, comprises an elongate cylinder housing generally at 76 suspended from hoisting line 71 and within which a hydraulic slave cylinder 77 and its rod 78 are protectively housed.

A pair of channel beams 80 with their flanged portions facing inwardly are spaced apart in a parallel manner throughout their length and receive therebetween the slave cylinder 77 the base end of which is coterminous the lower ends of the beams. Steel plates 81 extend the length of the beams welded intermediate the flanges thereof, said plates each supporting a length of angle iron at 82 which serve to guide the cable lift trolley as later describe-d. The lengths of angle iron extend upwardly from approximately the vertical midpoint of the channel beams as best viewed in FIGURE 10.

An upper pair of beam side plates 83 and lower side plates 84 secure the beams in their spaced relationship and extend therebeyond to receive, respectively, a hoisting line attachment pin 85 and a bucket assembly attachment pin 86. The line attachment pin is additionally secured within clevises 87 welded to an upper closure plate 88 for the channel beams.

Extending through the lower side plates 84 as aforesaid is the bucket assembly attachment pin 86 which as shown in FIGURE 11 extends also through a pair of flanges 90 depending from a bottom closure plate 91 for the channel beams. Upon this plate rests the base of slave cylinder 77 which base may be centered on the plate by adjust ment screws as at 92. Disposed above cylinder 77 to confine the same is another plate 93 through which passes the cylinders rod 78.

Positioned by the end of piston rod 78 is the cable lift trolley 94 having pairs of V-shaped rollers 95 for rolling guided engagement with the lengths of angle iron 82. Accordingly the outer or upper end of the rod is stabilized during upward movement which closes the clam shell members. The closing pennant 96 for the bucket is in the form of a cable having a double run, its ends terminating downwardly in attachment with the buckets pennant closing block 97 (FIG. 8) with its uppermost segment being received within a carrier block 100 which is integral with the trolley 94 above described. The cable lift trolley includes an inverted U-shaped holder 101 within which the carrier block is pinned in place by bolts. Accordingly it will be evident that any side loads imparted to the trolley will be borne by the V-shaped rollers instead of by the piston rod 78.

With attention to the lower end of cylinder housing 76 a pair of collars 102 gusseted at 103 and welded to the outer sides of the channel beams to receive the ends of the bucket assembly attachment pin 86 which is coterminous with the outer ends of the collars.

The lower end of one of the beams 80 is apertured to permit passage of a hydraulic conduit fitting 104 connecting the base end of the slave cylinder with a hydraulic line 105 which extends upwardly along the beam for attachment at 106 to a flexible conduit or hose 107 in a swivelled manner.

The bucket assembly is indicated generally at 108 and is capable of pivotal movement about the major axis of the attachment pin 86 relative to the cylinder housing 76 said movement being generally toward or away from the crane cab as viewed in FIGURE 8.

Attachment pin 86 also extends through pairs of upwardly projecting ears 111 best shown in FIGURE which are carried by a bucket head adapter 110 also shown in FIGURE 14 the purpose of the plate being to facilitate the combination of a substantially conventional bucket assembly with the novel closing means of the present invention. It is to be understood that the bucket structure used with the present invention may be one of the several commercially available which by modification of the adapter may be readily combined with the present closing means. In any bucket assembly selected the standard block and tackle closing therein will not be utilized and hence may be removed if desired from the bucketassembly.

The present adapter plate shown and described is for mounting the head of a bucket manufactured by the Esco Corporation and of a 2 /2 yard capacity. The inverted box-like adapter 110 best shown in FIGURE 16 includes front and rear rows downwardly extending rows of brackets respectively at 112 and 113 which are of concave shape at their lower ends to receive in a nested manner the bearing sleeves 114-115 of the bucket head. Since the bucket is known in the trade and conventional except as noted with regard to the block and tackle closing means a detailed description is believed unnecessary. In addition to the bearing sleeves, the bucket head includes head plates 116 to which the sleeves are welded, the head plates 116 extending upwardly into the bucket head adapter 110 and thereto attached by a bolt 117 extending through a series of depending apertured ears 120 affixed to the underside of the plate. Accordingly the bucket assembly may be separated from adapter plate 110 simply by removal of the bolt 117 which allows the bucket to be returned to conventional use upon simply re-rigging of a conventional closing line through its block and tackle closing arrangement. An upper pulley of such an arrangement is shown left in place at 121.

With continuing reference to FIGURE 16 the left hand bucket arms 122 are pivotally mounted while the opposite pair of arms 123 are fixedly attached to the bucket head by reason of their upper extremities being bolted in place by the bolt 117 as is conventional with the particular bucket assembly shown.

The bucket head adapter 110 additionally serves to mount pennant guides at its two sides in the form of cooperating pairs of sheaves 125. The two runs 96 of the closing pennant each pass between the closely spaced sheaves of each pair as typically shown in FIGURE 8, the sheaves serving to retain the pennant runs in vertical, parallel relationship to the cylinder housing 76 during pivotal movement of the bucket assembly about the axis of attachment pin 86. Each sheave is journalled on a stub shaft 126 which in turn is carried by a bracket 127 which is welded to the side of the adapter plate. It will be noted that the sheaves are located olfcenter of the adapter plate as best seen in FIGURE 16 as is necessary with the particular bucket shown. In the use of the present invention with other makes of clam shell buckets the same may be medially located on the adapter plate.

The remaining bucket assembly includes in addition to the moveable and stationary arms 122 and 123, the clam shells 130 and 131 with latter pivoting about its two arm attachment points 132 during opening and closing movement while the former moves about both the upper and lower arm attachment points 133-134. Both clam shells are hingedly attached at 130A-131A to the centrally disposed closing block 97 whose upward closing movement is imparted by like movement of the two runs 96 of the closing pennant. In bucket assemblies having a central pivot pin in place of the block 97 the pennant runs terminate in attachment thereto.

To permit convenient re-rigging of the bucket back into a conventional closing line arrangement the lower sheaves 135 of the closing block and tackle may be left in place on the closing block 97.

For pressurizing the lower or base end of the slave cylinder 77 a master cylinder 135 is carried adjacent the underside of the boom 74. In the present form of the invention master cylinder 135 rests on a supporting channel member 136 which is pinned at its lower end at 137 to a bracket support 138 affixed to the chassis of the crane cab. The master cylinder is also pinned at 137 to permit movement vertically with its support and the boom. Since the supporting channel member 136 and cylinder move about a separate pivot than the boom pivot mount the support member must be capable of relative movement to the boom and for this reason is retained at its upper end, as viewed in FIGURE 8, by means of a slide support 140. The supporting channel member may further serve to stabilize the outer end of the master cylinders piston rod 135A during rod movement. As in the first form of the invention the cranes closing line 72 is attached to the outer end of piston rod 135A as shown. Where sufiicient closing power is available the block and tackle arrangement 9 as in the first form may be dispensed with.

In continuing similarity to the master cylinder and fluid circuit of the first described form of the invention the cylinder 135 is filled with fluid above its piston, said fluid being exhaustible upon extraction of the piston rod 135A by take-up of the cranes closing line 72. The fluid is routed past a branch line 139 going to an accumulator 141, along fluid line 142 to a hose reel 143 which carries hose 107. The accumulator 141 is pre-charged to approximately 1,000 p.s.i. and accordingly since normal operating pressures are below with 1,000 p.s.i. no fluid normally enters the accumulator. Where normal closing of the clam shells is prevented and with the piston rod of the master cylinder fully extended the system pressure will have risen over the 1,000 psi. to cause passage of the hydraulic fluid into the accumulator to relieve the system from a rapid pressure increase. The accumulator is preferably of a fluid volume to permit temporary storage of an adequate fluid quantity under pressure to later actuate the slave cylinder in a cycle of operation when the resistance to the clam shells closing is lessened. In elfect the accumulator permits delayed closing at a point in time when an obstruction has been cleared or resistance lessened, such being accomplished without further retrieving of the closing line. In operations wherein the clam shells are not closed such as in the pulling of old piling desirable higher than normal fluid operating pressures are conveniently attainable.

The upper end or rod side of the piston of slave cylinder 77 may be charged with a head of air pressure if desired, by means of an air valve 79. While satisfactoy operation of the closing means is achieved with an atmospheric pressure it may be desired in some operations to pre-pressurize the upper end of cylinder 77 to efiect quicker retraction of the piston rod 78 and hence a more sudden opening of the clam shells.

The operation of the above described form of the invention appearing in FIGURES 8 through 16 is similar to that of the inventions first form. As shown in FIGURE 9 the bucket may engage an inclined or sloped surface in the desired relationship to the slope, i.e., perpendicular thereto, to accomplish a full bite whereas a conventionally suspended bucket will tend during closing to be rocked by the closing line upwardly about the clam shell offering the greatest resistance. In the dredging of an underwater sloping surface as shown in FIGURE 9 a conventionally suspended bucket would tend to be raised about the teeth of the uppermost clam shell upon tensioning of the closing line. In the present hydraulic closing means the reaction force of the slave cylinder is utilized to hold the upper ends of the bucket arms in place in relation to the surface of the dredged material thereby causing full penetration of the clam shells into the material fully loading the bucket.

The invention provides the highly desirable feature of a hydraulically operated closing pennant permitting the crane operator to initially fully retrieve the closing line and thereafter concern himself only with the hoisting line during bucket manuevering. The closing line of the crane since it does not attach to the bucket is not being retrieved or payed out with the hoisting line. Further the invention provides protection of the slave cylinder and its piston rod from damage by forceful damaging contact with an underwater obstruction. This is achieved by the use of a cable closing pennant in combination with the housed or protected piston rod of the slave cylinder.

A tagline 149 is attached to the bucket arms to prevent the bucket from excessive turning which turning adversely effects the life of the hoisting line cable. The tagline is slacked-otf during placement of the bucket to permit pivotal movement thereof.

In FIGURES 17 and 18 a gimbal mounting arrangement is disclosed for the slave cylinder housing. The advantage of the gimbal mounting in addition to permitting bucket assembly displacement away from the projected vertical centerline of the cylinder housing, is the lowering of the hydraulic closing means center of gravity in relation to the bucket assembly to increase bucket stability against any over balancing effect exerted by the closing means.

The cylinder housing 76 is the same as earlier described with the exception that it does not serve to mount a bucket attachment pin 86 at its lower end and hence may terminate in a flat end plate 146.

A first gimbal member 147 is of rectangular box-like shape closely fitting about the channel members of the cylinder housing and which member carries bearings 148 as best seen in FIGURE 18 to receive trunnions 150 welded oppositely to the lower side plates 84 of the housing 76.

For gimbal movement about a horizontal axis perpendicular to the axis of trunnions 150 a second gimbal member 151 also of rectangular box-like shape is pivotally mounted to trunnions 152 carried by first gimbal member by means of bearings 153. The second gimbal member mentioned serves to receive the upper ends of the bucket arms, the moveable arms being at 122 and the fixed bucket arms at 123.

Pairs of sheaves 155 earlier described in connection with the bucket adapter are in this modification carried by the outer gimbal member 151 and serve to hold the upwardly extending runs of the closing pennant 96 adjacent the cylinder housing.

Rollers 156 are provided below the sheaves for the purpose of correctly spacing said runs of the pennant away from the cylinder housing 76 during movement of the outer gimbal member 151 about the axis of trunnions 152. as shown in broken lines of FIGURE 18.

What we claim and desire to protect by Letters Patent is:

1. Hydraulically actuated means for suspension from the hoisting line of a crane machine or the like and comprising,

- bucket closing means including a pressure responsive cylinder adapted for upright suspension from the hoisting line of a crane and having a movable member terminating in operative engagement with a flexible load carrying member of said closing means whereby a lifting force is imparted to said flexible member and whereby load lifting movement of said flexible member may be along a vector out of parallel relationship with the downwardly projected axis of said cylinder, said bucket closing means further including a housing for said cylinder,

fluid pressure generating means for actuating said cylinder, and

fluid conduit means interconnecting said pressure generating means and said pressure responsive cylinder of said bucket closing means.

2. The invention as claimed in claim 1 wherein said housing is adapted for pivotal attachment at its lower end to a clam shell bucket assembly and said flexible member terminates downwardly in closing attachment with said bucket assembly whereby upon load lifting movement of said flexible member a simultaneous downward reaction force is imparted through said pivotal attachment to said bucket assembly.

3. The invention as claimed in claim 1 wherein said '11 housing includes rollermeans for guiding said flexible member.

4. The invention as claimed in claim 1 wherein said fluid conduit includes fluid pressure control means located adjacent said bucket closing means for a controlled lifting operation of said cylinder by an operator located remotely from the crane.

5. The invention as claimed in claim 1 wherein said bucket closing means includes a pulley block entrained on the cranes hoisting line and in pivoted attachment at the upper end of said housing whereby plural runs of the hoisting line may be formed to multiply the lifting capacity of said line.

6. The invention as claimed in claim 1 wherein said fluid pressure generating means includes a master hydraulic cylinder mounted on said crane machine and having a piston rod operatively engaged with and extensible by a closing line carried by said crane whereby upon extension of said piston rod by said closing line fluid pressure within the rod end of the cylinder will be transmitted through said conduit means to the lower end of the first mentioned cylinder for upward, load carrying retraction of the latters piston rod.

7. The invention as claimed in claim 6 wherein the piston rod of said master hydraulic cylinder carries a pulley block of a block and tackle arrangement utilizing a portion of the closing line.

8. The invention as claimed in claim 1 wherein said fluid pressure generating means includes an engine driven pump and operator controlled valve means for selectively directing fluid pressure to the underside of the piston of said pressure responsive cylinder.

9. The invention as claimed in claim 1 wherein said pressure responsive cylinder includes a piston having valve means for transferring of fluid under pressure from one side of the piston to the opposite side to permit scavenging of the cylinders chamber above said piston.

10. Hydraulic actuated bucket closing means for a clam shell bucket assembly, said closing means adapted for suspension from the hoist line of a crane machine and comprising in combination,

a pressure responsive cylinder having a movable memher,

a housing for said cylinder adapted for upright suspension from the hoist line of a crane and carrying the bucket assembly adjacent its lower end, a flexible load carrying member in attachment to said movable member of said cylinder and extending downwardly for closing attachment with the clam shells of said bucket assembly whereby upon upward movement of said flexible member to close the clam shells a downwardly directed reaction force is imparted by said cylinder through. said housing to said bucket assembly to retain same in position thereby overcoming the tendency of said bucket assembly to raise during clam shell closing,

fluidpressure generating means for actuating said cylinder,'and

fluid conduit means interconnecting said pressure generating means and said pressure responsive cylinder.

11. The invention as claimed in claim 10 wherein said bucket assembly is pivotally attached to the lower end of said housing whereby said bucket assembly maybe efliciently disposed perpendicularly to a slopedsurface being dealt with while said housing is disposed in an upright position, and guides for said flexible member being located adjacent said pivotal attachment whereby load lifting movement of said flexible member may be along a vector out of parallel relationship with the downwardly projected axis of said pressure responsive cylinder.

12. The invention as claimed in claim 10 wherein said movable member of said pressure responsive cylinder comprises the cylinders piston rod said housing protectively housing said rod and cylinder and including trolley means vertically positionable by said piston, said trolley means operatively supporting said flexible member.

13. The invention as claimed in claim 10 wherein said flexible member comprises a cable pennant having double runs extending downwardly into closing attachment with said bucket assembly.

14. The invention as claimed in claim 10 wherein adapter means are provided intermediate said housing and said bucket assembly whereby a conventional bucket assembly may be conveniently attached to said housing without modification of said bucket assembly.

15. The invention as claimed in claim 11 wherein said pivotal attachment of said bucket assembly to said housing embodies a gimbal permitting universal movement of said bucket assembly relative to said housing.

16. The invention as claimed in claim 11 wherein said gimbal is located superadjacent the lower end of said housing whereby the center of gravity of said housing is lowered relative to said bucket assembly.

References Cited UNITED STATES PATENTS l/l956 Walstrom 214-77l 7/1956 Bevan 2l4-l47 ANDRES H. NIELSEN, Primary Examiner 

